Microelectronic substrates and substrate assemblies typically include a semiconductor material having features, such as memory cells, that are linked with conductive lines. The conductive lines can be formed by first forming trenches or other recesses in the semiconductor material and then overlaying a conductive material (such as a metal) in the trenches. The conductive material is then selectively removed to leave conductive lines extending from one feature in the semiconductor material to another.
One technique for forming microelectronic features, such as capacitors, is to dispose the features in isolated containers within the microelectronic substrate. One typical process includes forming an aperture in a substrate material (such as borophosphosilicate glass or BPSG), coating the microelectronic substrate (including the walls of the aperture) first with a barrier layer and then with a conductive layer, and then overfilling the aperture with a generally nonconductive material, such as a photoresist material. The excess photoresist material, conductive layer material, and barrier layer material located external to the aperture are then removed using chemical-mechanical planarization or polishing (CMP). The capacitor is then disposed within the photoresist material in the aperture and coupled to other features of the microelectronic substrate with an overlying network of vias and lines.
One drawback with the foregoing container technique for forming capacitors is that during the CMP process, small particles of the conductive material removed from the conductive layer can become embedded in the photoresist material within the aperture. The embedded conductive material can cause short circuits and/or other defects in the capacitor that is subsequently formed in the aperture, causing the capacitor to fail. A further drawback is that high downforces are typically required during CMP processing to remove the conductive material external to the apertures. The high downforce can cause the conductive material adjacent to one aperture to smear into the conductive material of the adjacent aperture, which can in turn cause the adjacent containers to be short circuited to each other.